gWidgets (version 0.0-43)

gradio: Radio button group widget

Description

A radio group allows the user to select one value from a set of items. The items may be displayed horizontally or vertically.

Usage

gradio(items, selected = 1, horizontal = FALSE, handler
= NULL, action = NULL, container = NULL, ..., toolkit = guiToolkit())

Arguments

items

Vector of values to select from

selected

For gradio the initial selected value (as an index) For a drop list, the first selected value. Use 0 to leave blank

horizontal

A logical specifying the layout for gradio and gcheckboxgroup

handler

Called when selection is changed

action

Passed to handler when called.

container

Optional container to attach widget to

...

Passed to add method of container

toolkit

Which GUI toolkit to use

Details

The svalue method returns the selected value by name. If the extra argument index=TRUE is specified, the index of the selected value is given.

The svalue<- method can be used to set the selected value. One can specify the value by name or by index if index=TRUE is specified.

The "[" method refers to the vector defining the items.

The "[<-" method can be used to change the vector defining the items. For gWidgetstcltk the length can't change.

The "length" method returns the number of items.

See Also

The radio group is one of several widgets useful to selecting a value or values from a set of items. See also gcheckbox, gcheckboxgroup, gcombobox, and gtable

Methods for gComponent objects are detailed in gWidgets-methods.

Event Handlers are detailed in gWidgets-handlers.

Examples

flavors <- c("vanilla", "chocolate", "strawberry")

  w <- gwindow("Radio example")
  gp <- ggroup(container=w)
  glabel("Favorite flavor:",cont=gp, anchor=c(0,1))
  rb <- gradio(flavors, cont=gp)
  addHandlerClicked(rb, handler=function(h,..) {
   cat(sprintf("You picked  })

  betterFlavors <- c("coffee", "mint chip")
  rb[] <- betterFlavors ## tcltk won't be happy -- needs 3 flavors
  rb[] <- c(betterFlavors, "chocolate") ## to make tcltk happy
  
  rb[3] <- "mango sorbet" ## can change a label name

  ## set values
  svalue(rb) <- "coffee"  ## by name
  svalue(rb, index=TRUE) <- 1  ## by index

  ## get selected values
  svalue(rb)
  svalue(rb, index=TRUE)